Atheism doesn't have that standard because it's not that encompassing a thought. All athiesm is, is a lack of theism, period. It says nothing about morals or ethics. Your typical athiest, though, looks within to find what's moral or ethical and it usually just stems from what's acceptable behavior within the human species. This is also where religion gets its morality and ethics. But times change, and eating shellfish won't kill you, and eating meat on friday won't make the farmers go broke, so the morals and ethics change to fit the society.
Label: Non-Sarcastic